The present invention relates to a resin composition for an adhesive sheet and to an adhesive sheet using this composition for flexible printed circuit boards.
Flexible printed circuit board (FPC) has entered into widespread use as electronic and electrical machinery and devices have become thinner and lighter in recent years. During the mounting on FPC of electronic components such as resistors, ICs, and so forth, the FPC is glued through an adhesive sheet to a stiff reinforcing plate with the goal of improving the handling characteristics. The properties required of this adhesive sheet are, inter alia, a heat resistance capable of withstanding the solder reflow during mounting (solder heat resistance), adhesiveness for the FPC and reinforcing plate, and flexibility.
It is known that, for example, an acrylic-type adhesive composition comprising acrylic resin and epoxy resin can be used as an adhesive sheet that satisfies the aforementioned property requirements (refer, for example, to Japanese Patent Application Laid-open No. S 62-174283).
It is also known that an acrylic-type adhesive composition comprising acrylic resin, epoxy resin, and an epoxy curing agent can be used as the adhesive sheet (refer, for example, to Japanese Patent Application Laid-open No. 2003-231873).